[Association between XRCC1 polymorphisms and chromosome damage in workers exposed to benzene in jewelcrafting industry].

OBJECTIVE: To investigate the association between the gene polymorphisms of the DNA damage repair gene X-ray repair cross-complementing gene 1 (XRCC1) and susceptibility to chromosome damage in workers exposed to low-concentration benzene in the jewelcrafting industry. METHODS: A total of 286 workers exposed to benzene in jewelcrafting enterprises were enrolled as study subjects from January 2013 to December 2014. Gas chromatography was used to measure benzene concentration in workplace, cytokinesis-block micronucleus test was used to analyze the level of chromosome damage in peripheral blood, and the Sequenom technique was used to determine the single nucleotide polymorphisms of XRCC1. RESULTS: The time-weighted average concentration of benzene in workplace was <0.6~1.8 mg/m(3), lower than the national occupational exposure limit (6 mg/m(3)). The distribution of allele frequencies met the Hardy-Weinberg equilibrium in genetics (P>0.05). Increase in age (RR=1.38, 95%CI 1.06~3.75) and increase in working years (RR=1.45, 95%CI 1.18~2.58) were risk factors for the increase in micronucleus frequency. Compared with those with the wild-type homozygous genotype, the individuals with XRCC1 rs25487 CT genotype showed a significantly higher risk of increase in micronucleus frequency (RR=1.51, 95% CI 1.28~3.87, P<0.05) , and the individuals with XRCC1 rs1799782 AA genotype also showed a significantly higher risk of increase in micronucleus frequency (RR=1.65, 95% CI 1.30~3.12, P<0.05). There was no clear association between XRCC1 rs25489 polymorphisms and micronucleus frequency (P>0.05). CONCLUSION: Exposure to low-concentration benzene may cause chromosome damage in workers exposed to benzene, and the XRCC1 polymorphisms rs 25487 and rs1799782 may be associated with chromosome damage induced by benzene.

Protective effect of vitamin E on age-related alterations of Kupffer cell energy metabolism.

AIM: To investigate the mechanism of age-related reduction of Kupffer cell (KC) phagocytic capacity and the protective management. METHODS: Using rhodamine 123 fluorescence density and rate of glucose utilization as parameters, we measured the mitochondrial energy metabolism status in vitro and the glucose utilization capacity of isolated rat liver Kupffer cells (KCs) from rats of various ages (6 mo, 12 mo, 18 mo and 24 mo) and the effect of vitamin E (VE) pretreatment (500 mg/kg/wk × 13 wk). RESULTS: The rate of KC glucose utilization and the rhodamine fluorescence density of KC mitochondria of 18 mo-old untreated rats (NVEG) were significantly lower than that of 6 mo-old NVEG by 19.3% (4.0 nmol·h ± 0.4 nmol·h(-1) 10.6 cells(-1) vs 5.7 nmol·h ± 0.6 nmol·h(-1) 10(6) cells(-1), P < 0.05) and 19.5% (80.5 ± 6.3 vs 100.0 ± 4.7, P < 0.01) respectively; Rate of KC glucose utilization and the rhodamine fluorescence density of KC mitochondria of 6 mo-old rats were also lower than the 24 mo-old NVEG by 35.1% (3.7 nmol·h ± 0.6 nmol·h(-1)10(6) cells(-1) vs 5.7 nmol·h ± 0.6 nmol·h(-1) 10(6) cells(-1), P < 0.01) and 32.1% (67.9 ± 7.4 vs 100.0 ± 4.7, P < 0.01) respectively. The two parameters of 18 mo-old VE pretreated rats (VEG) were significantly higher than those of 18 mo-old NVEG, and statistically comparable to those of 6 mo-old VEG. The two parameters of the 24 mo-old VEG were significantly higher in comparison with those of 24 mo-old NVEG, but still significantly lower than those of 6 mo-old VEG. CONCLUSION: Aging has a significantly negative effect on KC energy metabolism, which can be alleviated by VE pretreatment.

[Genetic effects of mineral elements of Fe, Zn, Mn and P in black pericarp rice grains].

Complete diallel crosses with seven varieties of black pericarp rice were conducted in one year to analyze the genetic effects on main mineral elements of Fe, Zn, Mn and P contents in kernels of parents and their F1S and F2S, using the full genetic model including triploid endosperm, cytoplasmic and maternal effects on quantitative traits of seeds in cereal crops. The results indicated that the contents of all the four mineral elements were controlled by seed direct genetic effects, maternal genetic effects as well as by cytoplasmic effects. The seed direct genetic effects were more important than the maternal genetic effects for Fe, Zn, Mn contents, and seed direct additive effects constituted a major part of their genetic effects, whereas seed direct additive, maternal additive and dominant effects formed the main part in the inheritance of P content. The heritabilities of seed direct effects of the 4 mineral element contents were all highly significant. The estimate values of narrow heritabilites of seed direct genetic effects were high for Fe, Zn and Mn contents, while those of seed and maternal effects were intermediate for P content. Therefore, more attention should be paid to the single plant selection and single grain selection based on the seed mineral element contents of hybrid offspring.

[Diagnostic value of transbronchial lung biopsy via fiberbronchoscope of peripheral or diffuse pulmonary disease].

OBJECTIVE: To understand the diagnostic value of peripheral and diffuse pulmonary disease examined with Transbronchial lung biopsy (TBLB) via fiberoptic bronchoscope. METHODS: Four hundred and sixty patients of peripheral and diffuse pulmonary disease were diagnosed with TBLB via fiberoptic bronchoscope without fluoroscopic guidance. The result of clinical data and pathologic diagnosis were underwent retrospectively analyses. RESULTS: Confirmed diagnosis was obtained in 351 patients; the total positive diagnostic rate was 76.3%. Diseases were included lung cancer, pulmonary tuberculosis, diffuse interstitial pulmonary fibrosis, pulmonary sarcoidosis etc. The positive diagnostic rate of TBLB on pleural pulmonary disorders was the lowest. There were no any other serious complications except bleeding, blood sputum, fever and pneumothorax occasionally. CONCLUSIONS: TBLB in diagnoses of peripheral and diffuse pulmonary disease is a reliable, safe, handy cheap, may repeatable operational method.